cpp算法-图论-链式前向星

int cnt, head[maxn];
struct 
{
	int next, to, val;
}edge[maxm];
void add_edge(int from, int to, int val)
{
	edge[++cnt].next = head[from];
	edge[cnt].to     = to;
	edge[cnt].val    = val;
	head[from]       = cnt;
}